Breaking fast upon verifying that the sun has set and declined below the western horizon

Q: A group of people emerged in our town saying that they are staunch adherents to the Sunnah of Al-Mustafa (peace be upon him). But it is observed that they break fast in Ramadan and in other months at twilight (the time the sun is declining). They also say that the Hadith which they quote in support of their action is sound and authentic. What is your opinion with regard to this issue, our Shaykh?

A: Allah (Exalted be He) says: ...then complete your Saum (fast) till the nightfall and the Prophet Muhammad (peace be upon him) stated: When night falls from this side and the day disappears from this side and the sun has set, then the fasting person should break fast. (Reported by Al-Bukhari) Therefore, it is not allowed to break fast until the sun has completely set and declined below the western horizon, and the night has fallen in the eastern horizon. This can be ascertained either by witnessing the setting of the sun or by hearing the Mu'adhin (caller to Prayer) making the Adhan (call to Prayer) at the prescribed time.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.